Bio-chemical warfare for the dying
by Silvyavan
Summary: (Post-Kyoto) Rin is struck with an unknown disease straight after defeating the Impure King. This could be just seen as a last minute fever, but a plague crawls closer to True Cross. (Co-written with Faisalliot!)
1. Burning the blue Sea

Chapter one : "Burning up the Blue Sea"

Warning: Very very graphic depictions of pain, lots of suffering (sorry Rin), and this story is literally a horrible/demented combinations of shitposts, memes, tragedy, and angst. Be warned.

This is being co-written by Evilneko101!

Enjoy the story!

"OKUMURA!"

The first thing that registered in Rin's mind was hey! Suguro's already yelling at him again! Suguro limped up the only slightly destroyed cliff up to Okumura. He could still hardly fathom what the ever-loving fuck had just happened. He witnessed only moment ago Rin Okumura (Rin motherfucking Okumura! What the hell?!) defeat the Impure King (THE HOLY FUCKING IMPURE KING) by simply burning it down with what seemed to be the biggest kashou zanmai he had ever seen whilst (along with the theory that it had been, he still wasn't quite sure...) infused with blue flames.

"Suguro... Shura, I" Rin began, sheathing his sword back into its scabbard and swaying slightly in place.

The uneasiness that lingered in the air was seemingly thick enough to figuratively been cut with a dulled butter knife. The (human? demon?) practical savior of Assiah slowly turned to face both Shura and Suguro, and Suguro almost laughed at the odd (slightly constipated-looking) expression painted on Rin's face.

"I...I did it." Rin laughed breathlessly, allowing Suguro to let out a sigh of relief. "I-I controlled my flames! It's got a few kinks there and here, but I...I did it!" Rin called out excitedly.

With a half-hearted reprimand on his tongue, Suguro was cut off by the calls of his two childhood friends.

"Okumura-kun! Bon!" Konekomaru and Shima yelled sprinting full-throttle towards the three, tailed by a small group of exorcists.

"Koneko! Shima! You're both okay?" Bon fussed over his friends, stumbling over to them, Rin following behind with a slightly tired expression.

"Konekomaru! I did it! I didn't burn anything except for the Impure King!" Rin announced with a smile, huffing out a breath and holding out a thumbs-up. "I won't hurt you or your loved ones, I promise."

While Rin, Shima, Suguro, and the other exorcists exchanged praises and thank-yous, Konekomaru couldn't help but feel tears prick at his eyes, causing them to burn slightly.

"Okumura-kun...Thank you" Konekomaru uttered, his voice wavering as he began to sob with a mixture of regret and relief. "R-Really... I... Please forgive me and my actions!"

"Ahh, Koneko-san, don't take it so hard" Shima calmed his smaller friend, scratching the back of his head. Suddenly, he noticed Suguro.

"Eh? Bon?! You're still alive? I thought for sure you'd be dead by now."

"You didn't notice me walking towards you and Koneko just now?" Suguro muttered, sweat-dropping at his comrade's stupidity. "Honestly..."

"Sorry, I was caught up in the chaos. But, you're alright?" Shima bashfully smiled.

"Yeah, I'm fine, just a little tired and banged-up. Nothing major. Sorry for worrying you." Suguro shrugged.

"Haha, who's worried?" Rin chuckled, coughing a bit.

"BROTHER!" The shout startled Rin, and the group whirled to see Yukio darting towards them all, focused on Rin. The look of worry, slight bewilderment, and confusion could be seen blatantly on his face from where they were all standing.

"Oh,Yukio, you're okay too! I was going to start worrying in a...minute or two." Rin trailed off as Yukio ignored him entirely and proceeded to question Shura as to why his brother was out of the confinement. 'Ouch, that stung' Rin though to himself. 'He looks distressed though; maybe I should deliver some good news to cheer him up!'

"I saved all the people here! I bet you're so shocked that your jaws about to drop to the ground! The day I'll be able to surpass you is getting closer." Rin cheerfully called to his younger twin, pushing down a dizzy feeling that was starting to surface.

'Oooo, that sounded a bit weird. Mayyyyybe that didn't come out right.' Rin muttered in his mind when he saw the strange look on his twins face. Yukio began to walk towards him, and as he got closer, Rin could feel the negative aura coming from him. 'Oh shit.'

Yukio leveled eyes with Rin for a moment, and in the next, Yukio's fist collided harshly with Rin's cheek, causing crimson to spurt out of Rin's mouth.

'Yep. Definitely said it wrong.' Rin couldn't help but think.

"Don't be a FOOL!" Yukio yelled, yanking Rin towards him by the collar of Rin's hood-cloak.

Rin stared at Yukio in bewilderment, slightly stunned by his behavior. This wasn't like Yukio.

"Do you even understand the situation you're caught in!?"

Oh. That was like Yukio. Never mind.

The silence was almost palpable as Rin (kind of hazily) constructed a sentence in his mind.

"...I do."Rin finally replied, his head turned to Yukio's general direction even if it didn't seem like Rin was even looking at Yukio anymore. He was starting to feel a little...weird. "I...finally understood. I am-" Rin spat out a bit of blood, causing Yukio to draw back a little bit. "Satan's son. And I've spent all this time trying to run away and hide from that fact, but I can't exactly run away from what I am, can I? I can't change it...it's me. I'm me... and now I can accept that." Rin continued, his voice dying down to a hushed whisper near the end.

'What...what is this feeling? It's...it's starting to hurt.' Rin thought dimly.

"Brother?"

"Yu...kio." Rin mumbled, his eyes starting to close as the pain that was dull before began to grow in intensity. His lungs felt as if they were on fire.

"What's wrong?! Rin?!"

"I..I don't know...what's...what's wrong. I-It...it hurts..." Rin breathlessly whispered, collapsing to his knees.

"Be honored, youngling. Not every child of Satan gains the pride of being my container. " A strange voice whispered in Rin's head.

That's when things starting going down-hill.

Rin could faintly hear Yukio yelling at him and feel Yukio shaking him slightly, but he couldn't summon the energy to reply or so much as twitch. It was a miracle on it's own that he was still hunched over on his knees. He had the urge to vomit, yet he didn't feel light headed or the dryness of his throat that accompanied it. Or...it no longer felt like it? He couldn't tell. He had the urge to sleep, yet his body was refusing to let him pass out. Refusing to let him sleep. Refusing to let him give in to...to something. He could almost feel it trembling under his skin .

Rin instinctively felt his hand reach for his mouth as his throat gave out a small cough. For some reason, he felt liquid touch his lips and the taste of copper mixed in with the taste of something bitter and slightly foamy. He looked down at his shaking hand to see a handful of blood mixed in with another substance. It had bright toxic green color with lime and red little bubbles barely popping up due to the contact with air. This...this wasn't right. This wasn't good, this was really really bad. Rin was sure he hadn't ate anything remotely near to this alien color within these past couple days. He wasn't even sure if he'd eaten, actually. It could have been the miasma from the impure king, but he was positive that his flames burned it to the point of molecular ashes.

Another cough ripped through, stronger than the last. Pain rippled through his lungs as if they were being clawed at from the inside. Rin hunched over, a bone-shattering pain suddenly attacking his spine.

The small coughs escalated into a massive fit. He was sure he was going to cough out his own lungs at some point. He was too busy trying not to visualize his organs coming out and hanging from throat to notice that his brother's and friends' facial expressions had changed to horror and worry whilst asking him what was wrong. Vaguely, he felt Yukio stand up and yell for help, and heard the exorcists nearby frantically calling for a doctor while Yukio helplessly tried to soothe him. But, it was to no avail as the pain in his body was grabbing Rin's full attention. Several doctors raced up the hill and upon seeing Rin's state, immediately requested a stretcher.

Rin could feel Suguro trying to support him and keep him from falling the rest of the way to the dirt. Rin appreciated the notion, but it didn't help the pain much. The hand on his chest and back were slightly soothing though, but the feeling was quickly erased when Rin felt bile rising up in throat for the first time in quite awhile.

'Oh God, no.'

Rin suddenly keeled over and began violently vomiting whatever contents he had in his stomach. The vomit plopped sickeningly on the ground and Rin heard Suguro winced and draw back a bit, the comforting hand on Rin's back never leaving. Rin gasped for air, his throat burning and tears threatening to spill out of his eyes. He braced himself for more, knowing from experience that throwing up came in waves. Before he could request a bucket or something, the second wave of vomit emptied itself on the ground, enjoying the first one as it's company. He could almost feel the disgusted looks on the doctors faces. He ignored them as nothing but stomach acid forced itself out of his body.

Great, now wave number one and two have a friend. Thankfully, that seemed to be the last of it and Rin panted for breath, sitting back on his knees while someone brushed his sweat-dampened locks of black hair out of his face. Just when he was thanking whatever deity that had spared him for the time being, the coughing from before returned with vengeance. He could barely register it as someone lifted him up bridal style and laid him on a stretcher. He was carried away quickly, while he vaguely heard something concerning a temple. God, he could barely tell what was real anymore. Minutes seemed like hours and hours seemed like days.

Rin didn't know for how long he had been coughing, wheezing and occasionally spitting out blood with radioactive-looking substances, all he knew was that it hurt like all of hell decided to attack his nerves. He felt light burn his eyes as it entered his vision. He softly hissed at it, cursing whoever the hell invented light bulbs (Wasn't it Benjamin Franklin? Fuck, he didn't know. Curse him anyway.). His ears were ringing yet he could mildly make out doctors trying to attend to the wounded and those who weren't were helping them. Everybody was running around. His vision was blurry and he suddenly had an odd thought of headless chickens running around all over the place.

He faintly heard the sound of traditional doors opening and slightly cocked his head towards the noise.

"-n."

He heard his brother say his name (or was it someone else?) but his coughs drowned out the words.

"-in!"

"Rin! We're - to - you -icine. - Dow - "

In a brilliant moment of motivation and muscle coordination, Rin flipped himself off the stretcher and fell face first onto the floor.

The half-demon weakly and (whilst violently shaking due to post-tremors from all the coughing) propped himself up on his elbows, reaching up to hold his newly aching nose. Ouch. Thankfully though, the coughing had stopped. But only the coughing, unfortunately for him.

He felt someone lift him up (again; what was he, a rag-doll?) and lay him on a squishy futon and pull his shirt off. He hissed at the sudden attack of cold air on his chest and he forced himself to open his eyes, only to see Yukio pulling out stethoscope. He wheezed out in indignant protest when the cold metal made contact with his chest.

"...Yu...ki...o?" Rin huffed out, looking up at his younger brother with pain-addled eyes.

"Just relax, Nii-san. It's going to be okay. Now, tell me. Was anything in pain while you were coughing?"

"L-lungs." Rin coughed again. "Back."

Yukio nodded and reached forward, placing a warm hand on Rin's forehead.

"He's burning up." Yukio bit his lip as Rin's eyes drooped closed despite his best efforts. "Get some hot water, antibiotics and cough syrup. He can't, UNDER NO CIRCUMSTANCES, consume or ingest holy water."

Rin heard footsteps getting quiet and Yukio tried to change Rin into some soft night-clothes. Rin, on the other hand, was not exactly a great fan being stripped naked, whether or not it was Yukio or someone else stripping him down...

...Which resulted in 5 minutes of feeble struggling on Rin's part. Demon king level strength his ass, a cup would be able to do more than that.

The footsteps came back.

"We didn't have any antibiotics, but will cough syrup and ginger tea help?" Rin didn't know this person. He didn't know where he was, actually.

"It's good enough." Yukio sighed.

Rin closed his eyes. God he was tired, both mentally and physically. Right now, the only thing he wanted was to sleep, but the stupid light it the room was making it very difficult. He half-wished he had just fallen asleep on the way here, regardless of the fact he might've been forced to wake up anyway.

"Nii-san, you need to drink this." Yukio called, shaking Rin slightly. He felt something warm next to his face.

"Wha-?"-Rin managed to wheeze out.

"It's medicine."

Rin didn't want to comply, but whenever someone was sick, Yukio's word was law, for some reason. So, after a moment or two, Rin just decided to go with it and get it over with. Rin gave a weak nod as a hand wormed under his back and supported him. He felt something hot was pressed against his lips. At first he turned his head away, but began drinking it when he got used to the taste. The way the liquid entered his stomach made him shiver. It reminded him of his previous experience. Once he finished the tea, he made an effort to pick himself up, only to be pushed back down into the futon and have the blanket pulled over.

"You're really sick, Nii-san. This is the worst I've seen you, and you've been pretty bad before. You need to rest, please don't strain yourself." Yukio said in a quiet and calming tone of voice. "I'll get you a damp cloth. Stay here." Rin heard his brother's quickened footsteps recede from him and the sound of traditional doors opening and closing.

Yukio, on his way out, was kind enough to turn down the lights for Rin, realizing it was probably hurting his head. Rin sighed as the much softer light enveloped his aching body, and it didn't take much longer than a minute before he was dragged into sleep.

No one noticed his wheeze whilst his eyes rolled into the back of his head with dark nerves edging themselves on his neck,mouth and eyes.


	2. Delusion

The night before the next morning, Rin had been pretty sure that there was no possible way he would get any worse. It only took him about 3 seconds to realize how _fucking wrong_ he was when he woke up at 6 am. Rin turned his head to the side, wanting to ignore the churning in his stomach badly. It was far too early for another throw up session.

The rag on his head flopped to the side and fell on top of Kuro. He didn't see a bucket anywhere near him. ' _Fuck_ ' he thought. The churning in his stomach was growing much too hard to ignore and inwardly sighing, Rin slowly stood up on shaky legs, making his way to the next best option to a bucket; the window. Looking back he wasn't quite sure how the hell he made it to the window in the first place, considering by then the pain from before had only spread from his back to his limbs and head.

Crawling from the heavy futon to the window whilst avoiding everyone's futons made Rin feel like he had won an Olympic biathlon competition. It made him wonder why they would even put them in the same room as everyone else, if they could get sick too. The unsatisfying victory was short lived as water and something thicker made it's way up his throat. As much as he tried to be quiet, several yells of " _ack_!" and " _who's dying?_!" rose from behind him as he woke up several people by throwing up out of the window and into the conveniently placed trashcan outside the window _(lucky him_ ). After three waves of putrid stomach strain, Rin flopped on the window frame, his useless meat sticks (translation: legs) unable to support him any long. He could barely keep himself from falling over as it was.

Various voices flitted around the room, working their way into his skull and slamming against it. The floor seemed to rock like the deck of a boat beneath his feet and Rin briefly wondered if there was an earthquake going on or if he was just going crazy. The latter seemed the most accurate when he thought about it. Footsteps and a door slamming open registered in Rin's muddled mind.

"NII-SAN!"

 _Ah_. Yukio must've heard him puking out his guts.

He could feel two pairs arms hooking themselves around him and lifting him off the window. Rin hadn't had any energy to stand last night and neither does he have any today. After setting him upright, the hands pulled him to two shoulders and dragged him off. Rin thought that it might be Yukio and Shima, since they were there. To his surprise, Shiemi's voice rang near his ear. He was gently laid back into his futon and a hand reached out to stroke his hair away from his forehead, presumably to gauge how bad his obvious fever was. Rin could hardly understand nor process what Yukio said (or was it someone else?) before a rather frazzled Kuro sat on his face and curled up as if to protect him with the force of his cat butt.

'It could have been worse.' Rin blearily thought to himself. Kuro was lifted off his face, placed in the crook of his elbow (who meowed indignantly and Rin caught something along the lines of "GET YOUR PAWS OFF RIN, YOU HEATHENS!" somewhere within the cacophony of hissing), and a wonderful, cool, damp washcloth was draped across his forehead. The futon was tucked around him tightly, making him a little too warm as several steps vibrating over the floor. The sensations of, well, everything warped into pain and Rin could only whine at the contrasting ones with blurry eyes. For a moment or two he thought about asking Yukio to shoot him and put him out of his misery. Throwing up everything, coughing, all the weakness, and having feverish fits every half hour was bad enough; a heat stroke from being wrapped too tightly in the futon was definitely a nasty ingredient to throw in the mix.

He felt too hot in the futon and too cold outside of it (leaving him to use the one-leg-out technique). His churning stomach acid sent pain riveting through his lower half and made his hands tingle strangely, and his throat and vocal chord were wrecked to the point of only small amounts of water being able to help. Rin didn't quite remember when he fell asleep again, but next thing he knew, he was waking up once more. Rin opened his eyes and looked around, seeing that no one was in the room. He felt light-headed and his swimming vision was giving him hallucinations.

Feeling a bit more confident in himself, he rolled to his side and leveraged himself on his elbow and other hand. Slowly sitting up, he saw the door being slightly open.

 _'Ah, what a peeeeeeeeeerfect opportunity to go take a nice, refreshing walk!'_ Despite his better judgement screaming at him, it was drowned out by deliria from being overheated and Rin swayed to his feet. Blearily, Rin stumbled for the door. "You know what, I _REALLY_ need to talk to Suguro about something."He paused." But what?...

Eh, I'd remember later."

* * *

Twiddling his thumbs, Suguro faced his Dad. Rin was already putting his stress meter through the roof, but he had to do this before tackling what to do about his friend. First and foremost, he would be alleviating the tension between him and his dad by talking about the past years and resolving past issues like civilized, mature human beings. That didn't stop his father's piercing eyes from being any less intimidating as he questioned why Suguro had brought him to this private room.

"Ryuji? What's the matter? Why did you want to talk to me?"

Suguro took in a much needed breath and collected himself, clearing his throat. "I brought you here because I wanted to discuss old issues with you in hopes of...somewhat fixing our relationshi-"

"Uuuuuuuughhh..Some - someone..."

"...Did someone just _moan_?"

"I think it came from outside, but I'm sure that we're the only ones that know about-"

 _"Et mortuus est, et ego_ _**Deus**_..." repeated the same voice.

"Who the hell-"

A series of sloppy footsteps sounded down the hall, a slumped shadow falling over the traditional thin shoji paper door and, Suguro realized with a jolt, coming alarmingly close as the figure seemed to sway and fall. Suguro could hardly think ' _Oh shit_ ' before there was an almighty ripping noise before a figure fell through the fucking door itself, it's head slamming against the wooden floors with a horrible _THUD!_

Now, who was the only person Suguro knew who was stupid enough to walk around with a fever, pass out, and break through a paper door, thereby ruining what was supposed to be a meaningful and cleansing conversation?

The answer was obvious.

Rin Okumura was slumped on the floor, collapsed against the wood. Suguro could feel his blood pressure reaching dangerous levels.

"Um, Ryuji? Isn't that your friend?"

Suguro slowly counted down from ten, breathing deeply between the numbers.

"Ryuji?"

"Ooooooowwwwww. Wha' jus' happened?" Rin's tired voice slurred from the ground.

Composing himself, reminding himself that freaking out and screaming at people wasn't very effective, Suguro turned around and knelt down next to Rin.

"...I'll...go get his brother." Tatsuma awkwardly said, scurrying out of the room in search of Okumura-sensei.

"Go ahead." Suguro sighed, running a hand through his hair. "Now, you." Suguro sent a pointed look at the very disoriented and confused Rin on the ground.

"Me."

"Why on earth are you so insistent on ruining everything I try to do with the power of your sheer stupidity?"

"Wha'?"

"I was trying to talk to my dad and YOU just ruined it by falling through the fucking door. _Why are you out of bed?!"_

Rin's head fell on the floor and he slurred something unintelligible into the wooden floorboards.

"I can't understand you."

Rin rolled over only his back, his hand making a pleasing plopping sound on the wood. He stared up at the ceiling and said:

"How did I...get here?"

Suguro resisted the overwhelming urge to face palm.

"You tell ME! I DON'T KNOW!"

Rin seemed to suddenly remember something and sat upright, swaying a bit and brightly saying, "I went fer a walk!"

And just like that, Suguro (figuratively) _exploded_.

"YOU TOOK A WALK?!"

"Yea!"

"YOU ARE LIKE, DEATHLY FUCKING ILL! WHAT IS WRONG WITH YOU?!"

"I dunno."

"WHAT WERE YOU THINKING?!"

"I dunno."

"YOU BROKE THE _FUCKING DOOR!"_

"I did?"

Rin craned his neck to look at the door and stared at it as if surprised by the chaos he'd already caused. "Oops."

Oh, good God, Rin was delirious, wasn't he?

Rin suddenly brightened as if remembering another thing and passionately gripped Suguro's shoulders.

"Wai'. I jus remembered somethin'. S-Suguro."

"What?!"

"Just... Jus- fuckin listen you shit."

"I'm listening dumbass,just let me kick you back to your bed!"

"No, don' do tha'. Look, look. You're a cool dude and you shouldn't kick meh back t' mah bed. You also shouldn' be mean ta yer dad. Ya only got one, man. _Treasure_ him."

"Wha-"

"LISTEN!" Rin made a shushing noise.

 _What...the hell was he going on about?_

"I don't need to hear that from you!"

"YES YOU DO. **I'm** the one with daddy issues. You aren't allowed to have them too. That's **my** job."

"What the actual fuc-"

"LISTEN TO ME. Listen. NONONO. BAD RYUUJI. BE NICE TO YOUR DAD. You don't got three spare dads in your closet. You got one. I might have twoish, maybe one a half, but I still fucked up and I gots some mean daddy issues. That ain't cool. No being me."

Suguro's mind was swirling. ' _What in the world is going on_ ' he thought.

Rin stared at Suguro with fever glazed eyes and said: "M'kay?"

"...yeah?"

Rin held up a thumbs up, waited until Suguro held one up in return awkwardly, and proceeded to pass out once again.

What...the hell was that?

"NIISAN?! WHERE ARE YOU?!" Yukio's voice sounding from the hallway.

Awkwardly, Suguro approached Rin's body, gingerly lifted him up, and stepped into the hallway, looking to his very, very befuddled dad as if to say "we'll talk later."

"Okumura-sensei? He's...um, over here."

Yukio rushed to general vicinity to see Rin passed out with his clothes loosely hanging off his shoulders, laying limp in Suguro's arms.

"Oh, thank GOD! We've been looking everywhere!"

Yukio ushered Suguro to Rin's designated room, fretting over his twin all the while.

Dear lord. Rin just chewed him out for being a dick to his dad and now Rin's back was sweating and he wasn't even _conscious_. This was not how he imagined today, not in the slightest. Well, at least Rin had somehow managed to get to the bottom floor without breaking his nose on the stairs so that _was_ a good sign. It meant that he was hopefully getting better and the medicine was helping. Suguro pondered how the hell Rin had gotten to that secluded little room whilst climbing the stairs, carrying the halfling in his arms and thought about their conversation, if you could even call it that-

-Wait a minute. Did Rin say he had... _daddy issues_?


	3. Crows

From Rins experience in the past, he knows that fevers go by faster than they come.

He severely begins to greatly doubt his theory at eleven o'clock before lunch. He's getting really sick of being sick, no pun intended. He's barely been able to keep down his food, unless it's broth and even that came out nasty. He was feeling even worse knowing that he's keeping everyone back from going back to True Cross. This whole trip had been hell from day one and he's only had two or three good experiences. He sometimes wonders if the universe could be nicer to him. Maybe not. Who knows.

A three hours earlier, Yukio came by with herbal tea and medicine. An hour later and the garbage can was having a surprise vomit delivery.

Rin had no idea how he was still alive. Either hunger or lack of liquids should have killed him by now. It feels like it's been years.

He thinks like he's hallucinating because there's an actual flaming chicken on Suguros head when he sees him. In fact, Rin is seeing waaay too many things. Suguro and the flaming pigeon is one thing. The others are another.

The only two people that came with him that don't ooze a strange aura of something are Konekomaru and the puppet kid.

Izumo is surrounded by fog and mist with red and purple lines shifting every once in a while into the shape of fox ears and fluffy tails. He smells maple leaves and disinfectant when she visits him.

Shura has snakes swimming under her body. So many that you can see their outline perfectly. Snakes which open multiple eyes and sometimes slither out of the tattoo she has. There's ice and frostbites circling her skin around her waist and hips for some reason. She's almost like a walking winter.

If Shura was a walking winter, Shiemi was a shinning spring. Everywhere she walked, everything she touched was almost instantly surrounded by greenery. Flowers and vines wrapped around the corner of the walls when she was in the room. Long strands of grass wrapped themselves around anything she held from under her skin. And all of it glows in a warm yellow color. Every floor board is covered in moss, every door is wrapped in grapevines, every item is secured by hazelnuts and water lilies. Everything feels fresh and alive. She had the aura a god would have shown to their beloved. Like the sun itself had taken residence behind Shiemis head. He was almost lulled to sleep by this.

Then there was Shima. Dear lord, **Shima**. Shima was dripping ink and his footsteps burned black wherever he went into his room. Black bubbles came out of his mouth every time he spoke, tattoos crawling on his skin. If Shiemi felt like spring, the Shima had to be fall. Simply because of the feeling of something slowly dying or a false sense of security that is being given.

Really, Rin thinks he should tell Yukio. If only his brothers eyes weren't burning blue. Rin's scared of looking straight at him.

So yep, Rin was probably seeing too many things.

And this all happened today.

It's about three o'clock. Maybe even four. He's never seen a clock in his room so he's counting his fingers. It's been five fingers since Yukio gave him tea. That's rather long.

He decided to sleep. Sleeping the pain away would be better than suffering.

* * *

Mephisto was staring at Astaroth, greatly displeased. The brute had burst into his office, possessing Shiratori Reiji again. He hadn't expected a student of his to be possessed but this was Astaroth. Astaroth knew a good vessel when he saw one and was stubborn enough to break many cleanses for it. But his usual madness filled grin had been replaced by an angered sneer.

"Astaroth." Mephisto sighed." Please do tell why you were hellbent on ripping my office doors off their hinges just now?"

"You're the head of the Japan branch of those exorcists. Don't they pay you enough to replace them?" His tail swished in annoyance. Astaroth walked to the front of the desk and took a seat. "And we both know why I'm here."

"Oh? Well I certainly don't know. If it's something you want then you already know the answer. I'm not one for favors."

"You're serious, aren't you? You're a principal. Shouldn't you care about your students?" Astaroth leaned in, propping his elbows on his knees. "Your students are getting sick. Four are already coughing, two were sent to the nurse in the dorms. And that's just my floor. Don't get me started on the whole building. "

"Must be because of your foul coal tars, brother. You really don't know the meaning of subtle." Astaroth was the king of rot, meaning that the decay he brought with him comes with miasma and bacteria of any kind. Miasma and coal tars were a source of tuberculosis if inhaled enough. He was known for bringing quite a few diseases into the world.

"My coal tars shouldn't be even reaching them. There's an epidemic going on. People are coughing in the streets and for once it's not my fault. It's probably worse." Astaroth dug through his pockets to snatch his phone. Punching in the password, he tapped the gallery icon. "I fell as if you'd like to take a look at this." He turned the phone's screen to Mephisto.

Mephistos eyes widened. The picture was blurred by fog and it showed a seal of a black crow, rotting cuts shown on the body with a single green eye in its stomach. The bird was inside a circle, letting vines and spots weave around the wall. "The white dove falls for the white plague -"

"The black crow flies for the black plague. I know. I've been seeing them in the town more often than not. That thing is back. And it's getting closer." Astaroth finished bitterly. There wasn't much that he could say about the topic anyway. That thing had gone and wrecked havoc in their world once every few centuries. Almost as of to taunt them.

"Did you inform anyone else?"

"It's just you and me. But if Lucifer finds out, which will probably be sooner than later, it's going to be the pre-clone Era all over again. With his suicidal tendencies." Astaroth sneered. That had been a dark time.

"It's not supposed to be here. It took the closest thing to a legitimate vessels to Satan that we had. There's no improvement left. It has no reason to be here." Mephisto hissed. His nerves were pumping to the point where some were visible on his face. Trying to calm down, he began taking deep breaths.

"We don't know if this is a threat or just a curse spell." Astaroth told. Mephisto pinched the bridge of his nose and sighed. There was so much to deal with, he might need another bath. His hand slid down his face to cover his mouth.

"We just got rid of a headache, yet now we have to cure this infection. Just when we thought you were gone, you come back to haunt us so very gracefully."

"Headache? Wait, did you do something again?!"

* * *

Rin was woken up by sunlight creeping in through the window. His eyes stung from the light but he felt so soft. The futon was so warm and comfortable. Everything felt so easy.

After rolling around in the softness, away from the sun, Rin concluded that he was unable to fall back asleep. No matter how optimal the sleeping requirements were. He peeled the comforter off of his body as he sat up, suddenly having strength to do something. But what Rin was more concerned about was appeasing his loud stomach.

Walking out of the room, Rin realized how quiet it was. Then again, the sun just rose, so there might not be a lot of people up. Either way, that wasn't the problem. He had a mission to appease the demon on his stomach and he was gonna do it.

Walking down the hall, he made his way to the dining hall.

* * *

When Shiemi woke up to seeing the room having one too little occupants, she didn't think much of it. Only upon realizing that it was Rin who was missing did she wake the others. Rin was sick to the point of immobility and him suddenly disappearing raised red flags.

Yukio, upon hearing the news, immediately panicked. He hadn't told anyone about his encounter with Todo but... it doesn't deny that he could have gone after Rin because of him. In such an ill state, he's an easy target.

It's only after ten minutes of searching, they found him in the dining hall. Seeing Rin wolfing down food at the table, without a hint of sickness, Yukio felt relief.

"Nii-san, what are you doing?! You should be in bed, it's too early even for me." He walked over to him and used his right hand to pushed the bangs away from his forehead. Rin squirmed a little under the touch. "No fever? Rin how do you feel?"

Rin stopped chewing for a minute, thoughtful.

"Hungry." Yukio sighed.

"Nii-san, give me your hand. I need to check your pulse." Rin gave Yukio his left arm and was left confused. Then again he was sick, but today he felt infinitely better. Minus starving for anything and everything in the kitchen. After a minute of Yukio checking his watch, he stood up.

"Sixty beats per minute. Healthy, overall." Yukio concluded. It was strange though. His fever was bad enough that they would be forced to call an ambulance and turn him in to the hospital. But turning out perfectly healthy in the morning? Something seemed off. Even with Rin's demon immunity. "Nii-san, are you sure you feel fine? Any fatigue? Lightheaded or dizzy?"

"I'm fine, really. But I could go for some miso soup." Rin certainly had his appetite back. But the quick recovery was strange. Especially after such a bad fever.

"Okumura!" Ryuji burst into the hall. He looked disheveled and his hair covering his eyes. How early was it if even Suguro burst into the room looking half-asleep? " What the hell, aren't you sick? You can't just walk around the inn like that, someone might catch it!"

"Hey! For your information, I feel perfectly fine!" Rin pointed his chopsticks in an accusing manner. Suguro was taken back. Rin felt better? Last night Rin looked like he was dying from the inside out with a bad case of tuberculosis. Something that bad couldn't go away overnight. It was suspicious.

"Nii-san, you may feel better, but that doesn't mean that you're not sick anymore. I have to make sure you aren't actually sick, so we're going back to the room." Yukio grabbed Rin's arm and tried pulling away from the table.

"Oh fine. But I'm taking the food with me."

"Okay, okay. C'mon, let's go."

Outside of the inn, a crow was sitting perched on a branch. It's eyes were dripping green fluid and split into two. A third wing on the right folded in an unnatural angle. It stared as Rin, Yukio and Suguro left the dining hall and lightly jumped on the branch, flaring it's wings, cawing in glee and joy.

It flew off the branch towards the mountains, odd green ribbons fluttering from its tail.

It flew past lamp posts, above wire poles, and through trees. Flying past the trees, it saw its cloaked master waiting for it. Its master extended their arm and let the crow land on its hand.

Long nails, green nerves and tiny thorn bunches poked out of the hand. Another hand pulled a packet of crackers out of a pocket and let the crow take a single cookie from the packet with its mouth. The crow put the cracker in his claw and and began munching on the treat.

The hand put the packet back into its pocket and started petting the crow.

"Good news! Good news! Youngling is good vessel, good vessel indeed! Still alive, not dead! Good boy, good body!" The crow stopped munching on its treat to say that.

"Really? Well that's wonderful. I assume he's made a solid recovery?" Jagged teeth poked out of their mouth. Green liquid dripping with every word.

"Yes! Yes!" The crow chirped happily. Upon excitedly crowing, the cracker broke into two, one half falling on the ground. "My cookie! NO! " it ruefully cawed.

"Don't worry, you'll get another." The figure chuckled.


	4. Plague

Upon Rin's fever breaking, Shiemi was rather skeptical about it. She had her fair share of illnesses but none of them went away overnight. She wanted to question further on but decided against it. Rin was hardly concious during those two days and Yukio had been in a constant state of paranoia. Prodding about it wouldn't do any good.

On the bright side, they had enough time to go sightseeing! Ryuji was nice enough to show them some well known temples but Rin was hellbent on going to Kyoto tower first. So now, Suguro and Rin were bickering over where to go first, with Konekomaru and Shima trying to pry the both of them off each other.

"C'mon, you haven't been to Kyoto tower either!" Whined Rin.

"Yeah but there's a dozen of more interesting temples all over Kyoto! You can't just waste an opportunity like this on some shitty tourist attraction!"

"But what about the view from up there!"

Shiemi felt better, but for some reason couldn't shake the feeling that something was...wrong.

* * *

The True Cross Clinic was in shambles. More and more people were being admitted in that they could provide room. Children, teens, adults and even the elderly were showing symptoms all the way from flu to bronchitis. Coughing, wheezing and groaning filled the halls. Some cases were so bad that the ill had gotten into an accident and had to be sent to the ER. Nurses were running left and right, trying to administer medicine to lessen their pain.

Mephisto sneered. He was floating outside the hospital on his chair, watching the whole mess unfold. And this was only one of the hospitals like this.

Hospitals, clinics and university hospitals were getting stuffier by the moment. People were getting sick at an abnormal rate. Mephisto was prideful in his ways, but for _Astaroth_ to notice and him not? He felt as if he was being mocked by that thing.

But at the same time it was odd for it to rear it's ugly head again. It had taken the closest thing to a strong vessel in this world millennias ago. Did the fall of the Impure King disturb its aggressive point? The aggressor was the one that was overlooking their world. If its passive points pet was all of a sudden dead, it would have its revenge. Either with the start of another war or, in this case, a plague.

But the Impure King wasn't that special to the two of them. So now Mephisto was haunted by a question he hoped he'd never ask.

What makes what happened nearly six hundred years ago alike with what happened now?

* * *

When Yukio and their team got back from Kyoto, the last thing they have expected was to have medical masks shoved right in their faces. Five exorcists were wearing them but several were coughing heavily.

"What's all this about?" Yukio took his mask with much hesitancy.

"It's an epidemic. Over the past week, some sort of flu has spread at an alarming rate. Half the city has been infected. We were assigned to hand out sterilized medical masks to at least stop anyone from getting contaminated." The exorcists said as he put a mask over Konekomaru. "You all are from the Kyoto assignment, right? You're quite lucky as far as I'm concerned. People have been coughing their lungs out left and right."

"An epidemic? But we just got back from nearly getting doused in miasma! There's no way it could have reached True Cross." Izumo retorted, pulling her mask down a little.

"True, this is probably a group of high level demons' work, but it's rare to see rot demons working together. They're rather.." The other exorcist trailed off.

"Shit - mannered? " Rin retorted. He's had his fair share of rot demons to deal with.

"Yeah. Anyway, I don't advise you to stay out for long. It's getting colder and we're already low on staff as it is." They ushered them away from the train station.

That was an hour ago. After deciding to go back to their respective dorms, they parted ways. However, the more they went, the more they saw.

The world that was once there during August had melted into something new in September. People wrapped themselves in coats and scarves. A sea of medical masks walked the streets of shops, more closed and less open. Coughing and sniffing accompanied footsteps as fog and smoke stagnated the air. Faces of blurry and unfocused eyes walked the streets. Unease was left in the insides of the exwires as they returned to their dorm. Something was off not with just the people but the whole city.

Rin, however, felt even _weirder_. There was an odd force pulling at his insides, something pulling at him, almost as if whispering sweet nothingness into his ear. It was unnerving and nostalgic. As if soft cold hands were running down his back, trying to make him relax yet achieving the opposite. Like coming back to your childhood home but it looks like a haunted house now. It feels like home yet home has never felt so wrong. Something soothing yet cold kept swirling inside him.

Rin didn't think much of it so he decided that maybe he should just sleep it off.

He **did not** in fact sleep it off. He spent the whole night sleep walking with his eyes open. Whatever the feeling was, he hates it for taking away his sleep like the arse it is, giving him the hated enemy of a college students body - insomnia. Rolling around in the bed helped in no way. Walking around the dorms like a bored Poltergeist helped even less. Scaling the walls for shits and giggles then scaring the shit out of his brother who thought he was a huge cockroach waiting to eat him was only a little funny. Yukio had yelled at him to get off the ceiling and go to bed and threatened to knock him off it with a broom like the cockroach he's imitating. If he was going to run around in the middle of the night, he might be doing something productive.

That had given him an idea. He could bore himself to sleep! So he grabbed his physics book and got to work. He promptly fell asleep halfway through the eighth chapter - Electricity and the law of...something something.

Getting woken up by sunlight and Yukio vehemently asking why he's sleeping on his desk with a book stuck to his cheek was not as dreamy as it sounded. And for once he might actually get to school early, thanks to Yukio's coercion to the dark side of a good and healthy student.

Walking to school with Yukio without hurrying anywhere was rather peaceful. It reminded him of the time they would go to preschool together, hand in hand. It was nice. Even if the weather was shit and clouding everything with fog and coughs.

Separating at the academy halls, they made their way to their respective classrooms.

Upon opening the door, Rin saw that only a quarter of his classmates were present. Most were wearing face masks, some were even wearing scarves and knitted hats. It couldn't have been that cold, could it? Rin was perfectly fine with just his uniform and the face mask didn't do much. Plus the small amount of people was rather unnerving. Usually, the class would be full when he got to class. But perhaps it was still early and most were still on their way. It was pretty quiet as well. Might as well enjoy it.

By the time class started, only half the class was present, including Rin. The other half was sick and the teacher didn't look like he was fairing any better. Nonetheless, class continued.

But not for long. It was his sixth class and the teacher still wasn't present. The second bell had already rung and the teacher still wasn't present. Murmurs started to grow.

"You think Professor Mitsuki got sick?"

"Honestly, who's not getting sick now? Is this a plague or something?"

"You make it sound like it's the 13th century."

Someone walked into the class. It wasn't their teacher. She had apparently informed them that their teacher was hospitalized and that they were free to go back to their dorms. In fact, she had specified everyone to go back to their dorms. Until they found out where the disease was spreading from, classes would sometimes be put into self-study or even dismissed.

Class was dismissed.

The fog around the city was as thick as curry. Rin tried to see what was where, but could hardly see the shops on the road. He wondered if Yukio had gotten his classes cut short as well.

Cram school won't start for another hour, so he could just walk around town, wandering about. But something was different.

Some feeling of cold water running down jn droplets on his back was always present. He tried to shake it off but it still didn't let out.

He wondered if that one cafe that Ryuji told him about is open. He had come to cram and school with a mocachino on the go, gulping it down in one go. All nighters were something of a regular occurrence in the dormitories.

Walking about, he saw someone in the corner of his eye.

A person in a long messy poncho was walking about. The poncho was stuffed with feathers, furs, horns and even bones. Rotting flesh covered the tips and a large stuffy coat hid the stranger's hands but thy were missing pants, giving sight to bare feet. Long, untrimmed nails scratched the pavement while feet were bruised in more colours than Rin thought possible. A sleeve clutched an oxigen container with a mask that slid up their face. Their face was covered - one half by the breathing mask, one half by a crows mask with old glyphs. Miasma was floating out of the mask into the air. But what caused Rin's fight or flight response to kick in was the neon green liguid dripping from under the mask, little red chunks following with it.

Seeing that, Rin immediately turned around and decided to head to cram school early with a hasty pace. As he turned around, the figure suddenly appeared before him, yellow and green eyes peeking owlishly at him from under the mask.

Immediately, primal demon instincts kicked into the maximum. First thing that his mind could register?

 _Run._

His foot slammed into the pavement before he could think and started running down the street at breakneck speed. The figure followed. His eyes were glowing, satanic bloodline going into overdrive as instincts took over, gripping his sword like a life line.

Jumping over cars and down under bridges, Rin had used every parkour trick he had learned from television and watching people on the street.

* * *

Suguro, Konekomaru and Shima were walking back to the dorm as their classes were dismissed. The teacher had fallen ill and class was canceled for the day.

"And so I asked her-" Shima was about to ramble about a girl he was talking to when Okumura ran from the corner of the other street, flames in full blast and sweaty beyond belief. He grabbed a nearby telephone pole and used the force and the force of his run to fling himself into the other side of the road.

More specifically the second floor. He crashed into a window and bounced back with full force into a van, glass cutting into his uniform and skin.

"Okumura, _what the fuck?_!" Suguro voiced his shock and surprise before Rin snaps his head at them only to run the opposite direction. He was about to run after him for answers when another figure rammed itself into the same van, knocking it into a closed shop. The figure was left unscathed and immediately chased after Rin.

"I think Okumura-kun is in trouble! Bon, do you have your glock with you?!" Konekomaru frantically asked. Suguro started frantically searching in his bag for the gun. He kept it in his bag incase an emergency happened, but was sure to hide it properly.

He grabbed it and turned the safety off and they ran towards the chaser. Upon seeing them, Suguro aimed his gun at the stranger's feet. He shot one to the left foot and two at the right foot.

The two at the right collided, one grazing the ankle and the other going through the foot. The one to the left missed. The stranger cried out in pain, dropping to one knee as they used the oxigen tank to hold themselves up. They looked at Suguro, rage and miasma flaring. Before anything happened, a pink cloud sent them away.

As the pink mist clears, the next that happens is hardly believable.

They look around and see that they're back at the cram school but right next to them is Shiemi and Izumo.

The confusion is not that they're here, it's what's happening.

"Listen, humans, you hold it like this and you aim, but hold it close to your-"

Because Amaimon, the damn demon king of earth, is shoving guns into their arms and giving them the quickest lesson on how to use one and not hurt yourself in the process. Shiemi looks terrified as she holds the AK-47 and Izumo is looking at him with a shot gun in hand. Amaimon sees their arrival and quickly runs to the boxes sitting next to them. He looks again at them.

"Which one of you has skills in firearms?"

"What the hell is going on here?!" Suguro doesn't get an answer as Amaimon pulls out a bazooka and two sniper rifles.

He throws the rifles at Shima, who barely catches them, and reaches for the missiles.

"I'm going to make this as quick as possible, we're under attack, the cause is possessing someone very important and it's targeting Little brother. Astaroth is buying us time. When we get there, you shoot her legs and arms. Don't hesitate. Or else." Amaimon has a tone that could only bring pain. Pain that rips generations in half. Soon enough, he grabs the Infinity key in haste and shoves it into the slot. "Besides, we've got unfinished business with this _parasitic **cunt**._ "

He opens the door.

* * *

Rin's breath was shortening as he ran through streets, into cars and under bridges. His legs felt so numb he wasn't sure if he was still running or flying by the simple force of fear and rage. Nonetheless, he runs.

He doesn't need to take a look behind to know that the person chasing him is still there.

He ducks into an alleyway and runs to the other streets.

After fifteen minutes of randomly running, he ends up in a small square, far from the streets.

His breath is raspy, his knees were weak, his vision blurry but the old feeling never left him. He looks to the left, the right. Nothing. He breathes a sigh of relief.

He lost them, for now.

He's about to turn around and go home but-

Lo and behold, the medical hobo is behind him. The mask was removed and miasma spilled from it. The mouth of the stranger was sprinkled with blisters and cuts. But pouring out of it was the same green and red liquid that Rin had vomited barely half a week ago. Fear gnaws at him as he attempted to take a step back yet his body refused to move.

" Satan was a fool for letting someone as valuable slip under his fingers. Oh well, another vessel from that fire cracker is favorable to me." The voice is raspy and soft, and Rin feels sleepy. He feels his eye lids getting heavy. The stranger's hands move towards him. They're bony with untrimmed nails and scratches accompanied by bulging nerves. It's disgusting. So disgusting, Rin actually snaps back into reality.

"Damn it, when the fuck was the last time you touched a lotion bottle?! Those things are as crusty as my dad!" He yells. His face is horrified at the crusty hands. The figure steps back, confused. Their posture resumes as they try to grab him. Rin dodges the hands and takes two steps back.

"Hold still!"

"Fuck off!"

The cycle of yelling and grabbing continued until a rusty axe, roughly a head longer than Rin's hight, rammed itself into the stranger. The stranger falls back, roughly a few meters back. Rin's head whipped around to see his messiah, only to regret it.

Astaroth. Astaroth, who has definitely tried to kidnap him in the most unnerving way, had saved him. Rin can't tell if the development is good or worse. The horned demon runs in his direction and Rin prepares to throw a punch but he doesn't need to. Instead, Astaroth ran past him in a way that makes Rin question if he was trying to save him or just hit the stranger. The stranger is up but Astaroth makes haste in pulling the axe out and hitting them with the back of it. Perhaps a temporary truce is in need.

A pair of rough hands grab him by his waist and haul him off the ground. Rin whipped his head to see Amaimon, ready to throw him into the air.

"WAIT-" his shout goes unheard as he's flung twenty meters into the air. The whole world blended into a blur of building and colors as he spun in the air. Panic runs through his veins but is quickly stopped when he gets caught.

He sees Mephisto holding him by the scruff of his shirt in the air, standing on his favorite chair. Rin lets out a squeak when he realizes that he's thirty meters above the ground.

"So, how's it hanging?" The cheesy line practically rolled off Mephisto's tongue. Rin groaned. He didn't hate cheesy stuff like that but Mephisto made it sound less than tolerable.

" Oh, you know, being chased by a vengeful demon. The usual." A deaf man could hear Rin's sarcasm. However, Mephisto's face turned into a frown. He pulled Rin out of the air to stand with him on his chair.

"That's no demon." He said, looking over to the fight below him. Soon enough, the exwires joined Astaroth with Izumo shooting the stranger in the legs. Amaimon took the chance to kick them into the ground. It seemed easy enough.

Well, seemed.

Amaimons foot didn't even land as an arm grabbed his ankle and threw him at Astaroth. Miasma starting pouring out of the wounds and crows began to circle the sky. Rats crawled out the cracks of alleys and the paint, the plants on buildings and the windowsills began to decay. Crows started to morph into spears, bones crackling and flesh ripping. Several spears flew towards the demon kings. Amaimon uprooted a part of the asphalt to block them while Astaroth broke them with a swing of his axe.

Poisoned whips of water snapped at the demons. They grew out of the sleeves out of the stranger. Swinging them around themselves, the stranger let out a cry before letting out a storm of blows. Amaimon and Astaroth had to fall back, narrowly missing the shots aimed at them.

Mephisto began clapping, but it was sardonic and cynical. His attitude turned bitter and his eyes turned cold. Yet they were longing, looking for something.

"Well, well, look at what the rats dragged in. Never thought we'd see you again," Mephisto hissed. The next word he uttered had made a shiver run down Rin's spine.

 _ **"Pestilence..."**_


End file.
